Note 12 - Summary of Stock Options (Tables)

3 Months Ended

Mar. 31, 2022

Notes Tables

Share-Based Payment Arrangement, Option, Activity [Table Text Block]

	Three Months Ended March 31, 2022
						Weighted
				Weighted		Average
	Number			Average		Remaining		Aggregate
	of			Exercise		Contractual		Intrinsic
	Shares			Price		Term (years)		Value
Options outstanding, January 1, 2022		3,173,103		$	7.51		9.0	$	-
Options granted		941,000		$	1.26
Options exercised		-
Options canceled		(4,094	)	$	7.69
Options outstanding, March 31, 2022		4,110,009		$	6.08		9.0	$	-
Vested and exercisable and expected to vest, March 31, 2022		3,818,956		$	6.34		9.0	$	-
Vested and exercisable, March 31, 2022		995,692		$	15.65		8.4	$	-

Share-Based Payment Arrangement, Option, Exercise Price Range [Table Text Block]

							Weighted
			Number		Weighted		Average		Number		Weighted
			Outstanding		Average		Remaining		Exercisable		Average
Range of			as of		Exercise		Contractual		as of		Exercise
Exercise Prices			March 31, 2022		Price		Term (Years)		March 31, 2022		Price
$1.26	-	$1.26		941,000	$	1.26		9.8		39,212	$	1.26
$2.28	-	$2.96		2,207,000	$	2.73		9.2		387,341	$	2.73
$3.06	-	$3.40		10,000	$	3.20		9.0		1,833	$	3.26
$4.45	-	$4.80		11,900	$	4.72		8.7		3,832	$	4.71
$5.10	-	$5.40		88,000	$	5.28		8.5		62,563	$	5.34
$6.90	-	$6.90		5,400	$	6.90		8.0		2,700	$	6.90
$8.60	-	$8.91		827,800	$	8.69		7.7		481,974	$	8.69
$10.90	-	$13.60		15,500	$	12.64		7.9		12,865	$	13.00
$380.00	-	$9,920.00		3,409	$	2,878.01		6.0		3,372	$	2,890.61
Total:				4,110,009	$	6.08		9.0		995,692	$	15.65

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	Three Months Ended
	March 31,
	2022			2021
Expected term (in years)		6			5
Average volatility		88	%		87	%
Risk-free interest rate		1.43	%		0.82	%
Dividend yield		0	%		0	%

Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	March 31,
	2022		2021
Cost of revenue	$	65	$	55
Research and development		123		97
Selling, general and administrative		772		658
Total	$	960	$	810